Abstract

Stemming from the traditional use of field observers to score states and events, the study of animal behaviour often relies on analyses of discrete behavioural categories. Many studies of acoustic communication record sequences of animal sounds, classify vocalizations, and then examine how call categories are used relative to behavioural states and events. However, acoustic parameters can also convey information independent of call type, offering complementary study approaches to call classifications. Animal-attached tags can continuously sample high-resolution behavioural data on sounds and movements, which enables testing how acoustic parameters of signals relate to parameters of animal motion. Here, we present this approach through case studies on wild common bottlenose dolphins (Tursiops truncatus). Using data from sound-and-movement recording tags deployed in Sarasota (FL), we parameterized dolphin vocalizations and motion to investigate how senders and receivers modified movement parameters (including vectorial dynamic body acceleration, “VeDBA”, a proxy for activity intensity) as a function of signal parameters. We show that (1) VeDBA of one female during consortships had a negative relationship with centroid frequency of male calls, matching predictions about agonistic interactions based on motivation-structural rules; (2) VeDBA of four males had a positive relationship with modulation rate of their pulsed vocalizations, confirming predictions that click-repetition rate of these calls increases with agonism intensity. Tags offer opportunities to study animal behaviour through analyses of continuously sampled quantitative parameters, which can complement traditional methods and facilitate research replication. Our case studies illustrate the value of this approach to investigate communicative roles of acoustic parameter changes.

Significance statement

Studies of animal behaviour have traditionally relied on classification of behavioural patterns and analyses of discrete behavioural categories. Today, technologies such as animal-attached tags enable novel approaches, facilitating the use of quantitative metrics to characterize behaviour. In the field of acoustic communication, researchers typically classify vocalizations and examine usage of call categories. Through case studies of bottlenose dolphin social interactions, we present here a novel tag-based complementary approach. We used high-resolution tag data to parameterize dolphin sounds and motion, and we applied continuously sampled parameters to examine how individual dolphins responded to conspecifics’ signals and moved while producing sounds. Activity intensity of senders and receivers changed with specific call parameters, matching our predictions and illustrating the value of our approach to test communicative roles of acoustic parameter changes. Parametric approaches can complement traditional methods for animal behaviour and facilitate research replication.

中文翻译：

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使用动物附加标签参数化动物声音和运动以研究声学通信

摘要

源于传统使用现场观察者对状态和事件进行评分，动物行为研究通常依赖于对离散行为类别的分析。许多声学通信研究记录了动物声音的序列，对发声进行分类，然后检查如何使用与行为状态和事件相关的呼叫类别。然而，声学参数也可以传达独立于呼叫类型的信息，为呼叫分类提供补充研究方法。动物附加标签可以连续采样有关声音和运动的高分辨率行为数据，从而可以测试信号的声学参数与动物运动参数的关系。在这里，我们通过对野生常见宽吻海豚 ( Tursiops truncatus ) 的案例研究来介绍这种方法）。使用来自萨拉索塔（佛罗里达州）部署的声音和运动记录标签的数据，我们将海豚的发声和运动参数化，以研究发送者和接收者如何修改运动参数（包括矢量动态身体加速度，“VeDBA”，活动强度的代理）作为信号参数的函数。我们表明（1）一名女性在配偶期间的 VeDBA 与男性呼叫的质心频率呈负相关，匹配基于动机结构规则的竞争交互的预测；(2) 四名男性的 VeDBA 与其脉冲发声的调制率呈正相关，证实了这些呼叫的点击重复率随着激动强度而增加的预测。标签提供了通过分析连续采样的定量参数来研究动物行为的机会，这可以补充传统方法并促进研究复制。我们的案例研究说明了这种方法在研究声学参数变化的交流作用方面的价值。

意义陈述

动物行为研究传统上依赖于行为模式的分类和离散行为类别的分析。今天，诸如动物附加标签之类的技术使新方法成为可能，促进了使用定量指标来表征行为。在声学通信领域，研究人员通常对发声进行分类并检查呼叫类别的使用。通过对宽吻海豚社交互动的案例研究，我们在此提出了一种基于标签的新型互补方法。我们使用高分辨率标签数据来参数化海豚的声音和运动，并应用连续采样的参数来检查个体海豚如何响应同种动物的信号并在发出声音时移动。发送者和接收者的活动强度随特定呼叫参数而变化，匹配我们的预测并说明我们的方法在测试声学参数变化的交流作用方面的价值。参数方法可以补充动物行为的传统方法并促进研究复制。